Outflow boundary condition of multiphase microfluidic flow based on phase ratio equation in lattice Boltzmann method

2021 ◽  
Vol 33 (7) ◽  
pp. 073304
Author(s):  
Yi Zong ◽  
Min Li ◽  
Kai Wang
Keyword(s):  
Boundary Condition ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Phase Ratio ◽  
Ratio Equation ◽  
Outflow Boundary Condition ◽  
Microfluidic Flow ◽  
Outflow Boundary ◽  
Boltzmann Method

Numerical Simulations of Flows in Cerebral Aneurysms Using the Lattice Boltzmann Method

2020 ◽  
Author(s):  
Susumu Osaki ◽  
Kosuke Hayashi ◽  
Hidehito Kimura ◽  
Eiji Kohmura ◽  
Akio Tomiyama
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Flow Characteristics ◽  
Cerebral Aneurysms ◽  
Collision Operator ◽  
Velocity Model ◽  
Outflow Boundary Condition ◽  
Aneurysm Wall ◽  
Outflow Boundary ◽  
Boltzmann Method

Abstract The lattice Boltzmann method (LBM) is used to simulate blood flows in cerebral aneurysms and the effects of the outflow boundary condition on predictions are studied. The LBM utilizes the D3Q19 discrete velocity model, the multiple-relaxation time collision operator (MRT), and the interpolated bounce-back rule to treat complex aneurysm shapes. Flow characteristics in regions of a large fluctuation in the wall shear stress (WSS) were then investigated using the LBM to understand the relation between the flow structure and the aneurysm wall remodeling. As a result the following conclusions were obtained under the present range of the numerical condition: (1) even with significant changes in the flow rate distributions at outflow boundaries, the WSS in an aneurysm is not much affected if the boundaries are far from the aneurysm, and (2) the geometry of an aneurysm and the main artery largely affects the formation of large WSS fluctuation regions, which may thickens the aneurysm wall due to inflammation-induced wall remodeling.

scholarly journals Involving the Navier–Stokes equations in the derivation of boundary conditions for the lattice Boltzmann method

2011 ◽  
Vol 369 (1944) ◽  
pp. 2184-2192 ◽  
Author(s):  
Joris C. G. Verschaeve
Keyword(s):  
Boundary Condition ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Stokes Equations ◽  
Slip Boundary Condition ◽  
Navier Stokes ◽  
Grid Spacing ◽  
Navier Stokes Equations ◽  
Slip Boundary ◽  
Boltzmann Method

By means of the continuity equation of the incompressible Navier–Stokes equations, additional physical arguments for the derivation of a formulation of the no-slip boundary condition for the lattice Boltzmann method for straight walls at rest are obtained. This leads to a boundary condition that is second-order accurate with respect to the grid spacing and conserves mass. In addition, the boundary condition is stable for relaxation frequencies close to two.

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